Apparatus for baking



A. H. BALLARD.

vAPPARATUS FOR BAKING.

APPLICATION FILED ocr. 2|, 192|.

Patmted Oct. 31, 1922.

A. H. BALLARD.

APPARATUS Foa BAKANG.

APPLICAT|0N FILED OCT. 2l. 921. n 1,434,035. Patented Oct. 31, 191.2.

3 SHEETS-SHEET 2.

A. H. BALLARD.

, APPARATUS FOR BAKING.

APPLICATION m50 ocT.21,19zx.

Patented 0015. 31, 1922.

mms.

3 SHEETS-SHEET 3.

Patented @et 3l, 1922.

lil

isis

ARTHUR H, BALLARD, OF BOSTON, Tv'IASSACHUSETTS, ASSIGNOR T0 BALLARD OVEN CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATON OF MASSACHUSETTS.

APPARATUS FOR BAKING.

. Application filed October 21, 1921.

To all w /iom it may concern Be it known that I, ARTHUR lil'. BALLARD, a citizen of the United States, and a resident of Boston, county oit Suffolk, State of Massachuset-ts, have invented an Improvement in Apparatus for Baking, ot which the following description, in connection with the accompanying drawings, is a specilication7 like characters on the drawings representing like parts.

This invention consists in apparatus for baking7 one object being to provide in a relatively small, condensed space a baking oven oi the continuous type having a large capacity and capable ot' being used with liquid or other fuel and particularly tuel such as liquid hydrocarbon yielding high temperature products et combustion.

For illustrative purposes the invention herein shown as embodied in a bread baking oven ott relatively small dimensions and covering a relatively small superficial area, but provided with a traveling conveyor of large capacity on which thc loaves are conveyed into. through and out ot the oven. thc length ot the conveyor exposed to the heat ot the oven being relatively great as compared to the superficial area covered by the oven. ln the illustrated torni et oven indirect heating is utiliz/.ed7 that is to say, the products ot combustion are kept out oit direct contact with the material. which is conveyed through the oven tor baking, but are employed to heat properly located, highly conductive rzuliating surfaces ot' adequate area so arranged with relation to the combustion chamber that the high temperature products olf combustion may be conveyed to them by direct paths and be suitably di'liused or dis tributed thereover to effectively heat the oven at the required temperature and lnoperly apply the hea-t to the bread traveling through the same on the conveyor.

The invention will be best understood by reference to the following description when taken in connection with the accompanying illustration ot one speciiic embodiment oit the apparatus, while its scope will be more particularly pointed. out in the appended claims.

ln the drawings,-

Fig. l is a side elevation, partly in section, oi an oven embodying one iorm ot the in- Serial No. 509,320.

vention, that portion ot the conveyor external to the oven itself being shown only in part;

Fig. 2 is a transverse sectional elevation en the line 2-2 in Fig. l;

Fig. 3 is a detail elevation showing the construction ot the balile members in the vertical flue chambers;

F ig. l is asectional cle fation taken through one ot the battle members;

Fig. 5 is a diagrammatic view showing the path of the conveyor in its relation t0 the baking oven and the tempering oven;

`Fig. 6 is a sectional elevation taken through one ot the carrying trays;

Fig. 7 is a transverse sectional elevation taken through the carrier;

Fig. -l is a plan view oit one of the carrying trays; and

F ig. fl illustrates the details ot the bread discharging device.

Referring to the drawings and. to the einbodiment oi." the invention therein illustratcchthe baking chamber' ot the oven is contained within a structure which is herein shown as erected on a masonry setting il. (Figs. l and 2) within which setting is l0- catcd the combustion chamber. The oven structure is composed ot' horizontal and vertical tramc members 13 which may be of structural steel and provide support on the tour sides and top tor heat insulating walls. Herein such walls are constructed (Fig. 2) by providing a series et inner panels l5 and outer panels 17 `termed ot sheet metal with an intermediate insulating Vfilling l0 of any suitable material or materials,r such asbestos `or the like. The bottom ot the baking chamber is formed by the metallic iioor plate 2l separating the chamber trom the heating chamber below but serving a highly conductive radiating surtace to transmit upwardly to the baking space the heat received from the products o'if combustion. The walls iii' desired. may be so constructed as to leave door spaces 2O and one or more windo i spaces 24 so that access to the Oven may be had for purposes ot inspection or repairs and the condition ot the trays and their contents may be examined from time to time.

The oven chamber is preteably closed against the escape oit heat except where pro vision is made for the entrance and exit of the traveling conveyor, this being provided for in the present oven by cutting away the lower part of the front wall of the oven, as indicated in F ig. l, leaving an opening 22 or sutlicient size to permit the passage of the conveyor into the oven through the lower part of the opening and the exit ot the conveyor therefrom through the upper part of the opening. As hereinafter described, suitable provision is made at this entrance-exit opening to oppose the escape of heat therethrough. i

The traveling conveyor may be ot any suitable construction, but herein consists of a pair ot' chains 28, to each or' which are jointed at suitably separated intervals depending supports 25, there being sustained between each pair of supports a carrier tray 27 serving to hold the pans or other receptacles in which the individual loaves of bread or other materials to be baked are car ried through the oven. The detail construction of the trays and the pans will be hereinafter more fully described.

The conveyor chains may be driven at any suitable point, as by the driving sprockets S7 located at the exit end ot the oven chamber, any suitable driving power being utilized, as, for example, a motor` and gearing (not shown) designed to give the required rate of feed to the conveyor. The sprocket chains are guided at suitable intervals within the oven by guiding sprockets 31 journaled on the inner walls of the oven chamber and so located as to guide the conveyor in a circuitous path which doubles or returns on itself preferably a number of times, so as to expose within the relatively small space of the baking chamber a considerable length ot conveyor.

Referring to Fig. 1, it will be seen that the conveyor enters the oven chamber in a horizontal path through the opening 22 at the bottom thereof, passing around the guicL ing sprockets 31. and is then directed into a 'vertical path. As it passes over a pair of larger guiding sprockets 33 near the upper part of the chamber it takes a vertical downward path until it reaches the bottom of the chamber, whereupon it passes over another pair ot guiding sprockets 31 and again assumes an upward path. This is repeated a number of times until the length of the baking chamber has been traversed, whereupon the conveyor engages the guiding sprockets 31 near thetop of the oven and is directed in a substantially horizontal path near the top of the oven back to the torward'end thereof and thence down and out ot the entrance-exit opening 22. Each carrier tray, being suspended from a point above its center ot gravity, maintains the same upright position at all times irrespective oi? the direction ot travell of the conveyor. Guide supports to engage the ends of the trays or the chains themselves, in the form of fixed guiding rolls (not shown) at the sides of the baking chamber, or any other suitable means, may be employed to prevent the carrier from sagging in its upper horizontal path under the weight of the bread. The conveyor may also have any ordinary or usual devices (not shown) for maintaining suitable tension in the sprocket chains and to offset the expansion whichtakes place when the oven is heated.

.Referring now to the generation of heat and the provisions for applying heat to the bread as it is conveyed through the baking chamber, the combustion chamber 35 is enclosed by vrefractory walls being herein formed by the brick arch 37. The rear end of the combustion chamber is closed by the refractory wall 38 having one or more air admission passages 40 and having also projecting through it and into the combustion chamber the crude oil burner 39 which may be of any usual or ordinary type, and provided with well known devices (not shown) tor varying the relative supply of air and oil and regulating the temperature to the requirements or' the materials being baked. The opposite end of the combustion chamber opens into a combustionv space 11 formed by the bridge wall 43 and opening into the heating chamber 45 above the arch 37 and directly beneath the oven Jdoor 21. The sides ot the heating` chamber L15 are termed (Fig.

bv kthe refractory walls i6 on the top of which rests the i'loor 21.

By providing a separate combustion chamber with refractory enclosing walls, the high temperature products or" combustion may be generated and the combustion completed before reaching the radiating surfaces, and a uniform distribution ci? the heated. gases to the radiating surta-ces may be provided tor. At the same time the location ot the combustion chamber beneath the baking chamber permits the ascending radiation .trom the combustion chamber to be availed oi? in raising the heat of the bal"- ing chamber. The etliectiife application of the heat of combustion to the baking chamber is also increased by the provision ot the flue or heating chamber 4:5 between the combustion chamber and the baking chamber, provided, as it is, with the metallic radiating surface 21 underlying the conveyor through which the heat ot the products ot combustion received from the combustion chamber effectively transmitted to the baking' chamber in an ascending path.

The substantially flat baking chamber floor 21 provides a radiating surtace which underlies the conveyor and the baking space, where it is most effective both for efficient application and uniform distribution oi the heat. The circuitous path ot the conveyor.

. same in the form of pairs oi" sheet metal partition walls .el-9 oi' high heat 'conductivity which extend transverselgv across the oven chamber, oreferably 'from side to side, having communication 'through the floor 21. with the heating space #t5 and at the top with a s vsteni. oi'? dues to be described, such partition. walls thereby providing upright heating or flue chambers 5l which are distributed throughout the length ot the balting chamber and are so related to the conveyor as to most effectively direct the heat against the bread traveling therethrough. lhree such chambers intermediate the ends are herein provided, as indicated in Fig. l, located beneath the respective guide sprocket wheels 33 so as to stand betweenthe tiers ot upwardly and downwardlj,Y moving trays. tt the rear end ot the oven there is also provided a iiue or heating space 53 formed between transverse partition walls 52 and adapted to carry the products of combus-l tion from the rear of the heating; chamber upwardly and out of the baking chamber through a pair ot iiue exits 5o' at the top thereof. The transverse partition walls 52 are preferably ot metal and serve as additional radiating surfaces.

' The construction ot eali upright transverse heating or flue chamber 5l will be seen 'troni Figs. l. `to et inclusive, rvhere details ot the second one ot the series are sl'iown. rlChe two partition walls ffl-9 extend transversely across between the Side walls ot the oven chamber formingthe 'heating or flue chainber 5 l which. is closed at the top by the plate and at the ends by plates 58, leaving a space above the chamber 5l sutiicient to permit the passage ot the conveyor over the same.

lit will be seen that the several intermediate heating chambers 51 and end chamber 53, together with `the erit tlues, are torined bv walls which are separate trom the insulating' side walls of the oven itself so that the struct-ure'ot' the baking chamber in cltect is built around the described `tine sjistem, therebj7 providing a system. of tlues within the halting' chamber space and presenting radiating surfaces which have a mum. heatii g; e'itt'ect.` driiisiicn oit the products ou combustion from the heating chamber t5 to the tlue or heating chamber 5l (see Fig. 2) takes place through an opening in the floor 2l which provides a throat or passage 59 leading into the upright flue chambers kand extending across the heating chamber Ll5 between the refractory walls to. 'lf o insure unitorin distributionJ the chamber il is provided with a series oil? transverse battles (il which may be oit an;T suitable construction, but herein (Figs. and et) comprise sleeves supported by bolts fastened to opposite plates t9 and passing through the Hue chamber. The battles 6l., which are arranged in two upwardlyv converging sets, are so located and spaced with reierence to the exit openings (35 trom the iiue chambers that they compel the products rof combustion entering the passage 5) to distribute themselves throughout the entire space oit the rlue chamber and heat each radiating surface t9 uniformly but without an excessive heat at {in}T one part thereof.

i Exit openings are provided each side oi each tlue char an d communicate with a System ot 'lines 67, also preferablyY oit metal. to present additional radiating surfaces, extending along opposite sides oit the oven where thej,7 do not interfere with the passa-ge oil. the bread trays carried bv the conveyor. These latter Vdues GT communicate in succession with the succeeding ilue chambers 5l and convej,Y products ot combustion into the back liuc chamber 53 at the Abac-lt of the oven chamber. The crosssectioual. area ol the lines 6? preferably undergoes a gradual enlargement as they pass successive upright this chambers. ln the-illustrated embodiment of the invention, auxiliar)T branch tlues 69 are provided to further increase the capacity ot these enit itlues,

rllhe path provided for the products of combustion and `the arrangement of' the radiating surfaces will now be clear. in the heating chamber 45, products of completed combustion emerging troni the combustion chamber are brought in contact with the radiating floor sui-tace 2l, which latter absorbs a part oil. the heat and radiates it into `the bottoni of the oven where it meets the upwardlvl and downwardly moving sets of bread pans. At the iirst upright heating chamber 5l a portion oit' the products of combustion are diverted into a vert-ical path through the throat 59 and pass into that' chamber, and the same thing takes place at the open throat ot each successive upright tlue cfliainber. rlthe balance ot the products ot combustion pass alone' the bottoni ot the floor 2l to the rear end or the heating chamet, whence thev pass into the end or rear vertical tlue 53 and ascending cally pass out ot the oven through the enns 55. ln each upright hue chamber the hot gases entering the throat '(llig. 2) travel up toward the two horizontal lues 67 at the side of the oven which they enter through the opening 65, but, owing to the arrangement of bailies 6l, in so doing, they are spread and distributed so that they are brought in contact with substantially every part of each radiating plate i9 and the two plates are thereby heated uniformly and without tendency to have theirlower or yany other portions overheated. n

. To apply the high temperature products of combustion directly to the radiating surfaces' from the combustion chamber while at the same time to distribute them uniformly without overheating, the combustion chamber 35 is preferably tapped at intervals tlireughout its length. to cause a more uniform distribution of the hot gases therein than would be alforded were they all cempelled to pass through the combustion space el.

.Any suitable arrangement of exit passages may be provided, but herein the arch is provided not only with lateral distributing openings "Il (Fig. l) but is also provided with elongated slotted ports '723 which are located approximately beneath the second and third. rear flue chambers 5l and provide suitable exit openings for thev gases to feed these chambers with he products of combustion direct from the combustion chamber. Herein the ports i3 extend entirely across the crown of the arch, as indicated in Figs. l and 2, but are preferably gradually narrowed as the top of the arch is approached, as shown in l. This reduces the cross sectional area of the port at the top of the combustion chamber and insures a more uniform distriluition of the high temperature products of combustion to the various radiating` surfaces which are utilized to distribute the heut to the oven.

It will be seen that the bread pans carried by the c-anveyor` after entering the oven, pass over the first pair of guiding sprockets 232i? when-alpen the material to be baked is brought into close proximity to the rear radiating wall i-9 of the rst upright heating cha bei' approaching all the time the floor radiating surface 2l. On assuming an upward path of travel they are then brought into proximity to the front radiating wall 4 9 of the second uprightchamber 5l, next into proximity with the rear wall thereof, and so on until the entire length of the oven has been traversed. In their return path and before withdrawal they are carried the entire length of the oven near the top thereof, which is heated by the ascending` cur,- rents of air from all the lower radiating surfaces.

ln dealing with high temperature products of combustion, such as are vynoduced by liurning crude oil, in order to indirectly heat the baiting chamber efficiently and effectively, it is desirable to employ radiating surfaces of relatively great aggregate area and to so apply the products of combustion to the heating thereof that they reach the radiating surfaces by relatively direct paths nfrom the combustion chamber and that they undergo a suitable dis ribution and diffusion over the radiating surfaces so as to secure a uniform heating thereof without excessive concentration of the heat on any one portion of the radiating surfaces. By the described arrangement the radiating surface of a relatively sinall oven can be increased to secure an efficient transfer of heat, and the high temperature resulting from the combustion of the hydrocarbon fuel can Abe eiiectively applied to heat the oven and the heat thereof uniformly distributed without excessive heat in any one part thereof.

rlhe relatively great metallic radiating surfaces contacting with the products of combustion in the heat distributing space or spaces provide radiating walls of high conductivity capable of being quickly heated and quickly cooled, so that the oven may bc started up when cold or cooled down when stopped in a minimum of time. The products of con'ibustion are generated in the combustion chamber which protects the radiating surfaces from excessive heat. @n the other hand, they are applied directly and eectively to the radiating surfaces without waste of heat in transmission and quiclrly diliused and distributed over a wide area of radiating surface by the arrangement of ports in the heating chamber. lt will be observed that the general distribution of the products of combustion is upward out of the combustion chamber to the bottom of the baiting chamber, and thence upward through the interior flues arranged in close proximity to the carrier, thence horizontally and upward through the top of the bal'ingi chamber, this taking place through multiple paths which provideforthe direct but relatively uniform and effective application of the vheat from the combustion chamber to the radiating' surfaces of the baking chamber. l

Referring to the front of the oven and the entrance-enit opening for the conveyor, I have made provision to minimize the heat loss and oppose the escape of het gases therefrom. Referring more particularly to Fig. l, there is preferably provided a vertical partition wall or bailie plate which preferably extends entirely across the oven located between the ascending line of trays on the entering line of the conveyor and the descending line of trays on the departing line thereof. The descending line of trays moves in close proximity on one side of the partition will .75 and in close proximity on the other side to the oven wall 13. The ascending line of trays moves in close proximity vlos;

of their respective pans, as the latter are tilted on the sides, Iare allowed to gravitate down Y an inclined chute 113, whence they may be conveyed, as by the 'underlying' transversely traveling' conveyor belt 115, to any suitable point of delivery. The entire operation of disclrargin1` the baked bread from the trays and conveying it away from the oven can thus be performed automatically.

rfhe provision of the vertical entrance passage for the conveyor which is substantially closed at all times by one or more tra-ys, and; the provision of the baffle plate '77 not only prevent the loss of heat but increase the sharpness or tb e suddenness of the first heatin` effect of the oven securing,` the effect of a flash heat which is Aeffective to form a crust over the outside of the bread before it has been subjected for any substantial time to the baking operation. Thus the loaf asv it enters the oven is kept comparatively ,cool until about the time it emerges from the vertical ent-rance passage, after which it is quickly and without substantial loss of time brought into close proximity to the highly hea-ted radiating surface 49 with the effect forming a thin, hard outer crust. The hard crust, which is thus secured by the sudden exposure to the full heat ofthe oven at the outset, permits the retention of the maximum amount of moisture in the loaf during` the subsequent baking operation and prevents the ,gradual Withdrawal of moisture which would oecur if the loaf were caused to approach the hottest part of the oven by exposure to gradualw ly increasing temperatures.

While I have herein shown and described a baking oven intended more particularly for utilization of hydrocarbon fuel, many features of my invention are applicable to ovens employing other fuels, and while I havedescribed more specifically the operation-of baking bread it is to be understood that the invention has application to widely different uses.

. Moreover, while there is shown and described for the purpose of illustration one specific embodiment of the invention, it is lto be understood that the saine is not limited to the mechanical details or to the form or arrangement of parts, but that extensive deviations may be made therefrom without departing from the spirit thereof.

Claims 1 f l. A continuous baking oven comprising in combination, baking` chamber, an endless traveling conveyor with carrying devices for the materialsto be baked, means to guideth'e conveyor into and through the chamber in an elongatedpath providing a plurality of up and dovvn paths, a combustion chamber having' refractory wals beneath the baking cluunber, a hydrocarbon burner for said combustion chamber, a heating chamber between the combustion chamber and the baking chamber, a metallic radiating floor wall for the baking chamber exposed to the heating chamber, other metallic radiating walls extending between the up and down paths of travel of the conveyor and heated by the products of combustion passingthrough the heating chamber, said combustion chamber having a plurality of exits distributed lengthwise the same to distribute the products of combustion to the heating' chan ber and the said other radiating` walls.

2. A continuous bakingoven comprising),` in combination, a baking chamber and an endless conveyor for the materials to be baked, a combustion chamber with refractory walls beneath the baking cham er, and metallic radiating walls Within the baking` chambe heated by the products of combustion for the indirect heating of the material to be baked, and including a metallic radiating floor Wall for the baking chamber.

3. A continuous baking oven comprising in combination, a baking` chamber and an endless conveyor for the materials to be baked, a combustion chamber havingrefractory walls, a flue chamber communicatinnr with the combustion chamber and havin@im substantially horizontal metallic radiatinig,v walls heated by the products of combustion therein and exposed to the 'baking chamber, and additional flue chambers extending,- into the space of the baking metallic radiating` Walls.

l. A bakiim oven having in combination` a bakingl chamber, an endless traveling?,` con veyor for the materials to be baked, a combustion chamber provided with refractory walls, a flue chamber beneath the baking chamber communicating with the combustion chamber and having metallic radiating walls exposed to the baking chamber, and a plurality of flue chambers provided with metallicv radiating walls extendingthrough the space of the baking chamber and communicating with said first named flue chamber for conveying the products of combustion from the first flue chamber through a plurality of paths. Y Y

5. A continuous baking oven comprising a baking chamber, an endless conveyor' with carrying devices for the materials to be baked, a combustion chamber beneath the bakingchamber having refractory walls, a

flue chamber over the combustion cha-nil' the bottom of the baking chamber hichulingr a metallic radiating wall heated by said iiuc chamber, and said combustion chamber having exits distributed lengthwise the same to distribute the products ofcombustion to said radiating Walls.

6. A continuous baking oven comprising in combination, a baking chamber separate from but comnuinicating with the combuschamber also having tion chamber, an endless traveling conveyor, a combustion chamber, a heating chamber beneath the baking chamber, and a plurality of flues communicating with said heating chamber and having heat radiating Walls eX- posed to the materials to be baked and presenting divided. paths to the ascending products of combustion.

7. A baking oven having a baking cham-` ber, a traveling conveyor, a metallic heat radiating ioor for the baking oven, an arched combustion chamber with refractory Walls, a heating or flue chamber between the combustion chamber and the radiating floor, a hydrocarbon burner for one end of the co1nbustion chamber, the opposite end thereof being open to the heating chamber above, and intermediate exits from the combustion chamber to the heating chamber.

8. A continuous baking oven having a baking chamber, a traveling conveyor, a co1nbustion chamber beneath the baking chamber, a flue chamber between the baking chanibei and the combustion chamber having radiating Walls exposed to the baking chamber, and exits to distribute the high temperature products of combustion to the iiue chamber at different points lengthwise the baking chamber.

9. A continuous baking oven. having a baking chamber, an endless traveling conveyor provided With carrying devices for the material to be baked, means for guiding the same into and out of said chamber near the bottom thereof, heat radiating surfaces Within said baking chamber for the indirect heating of said baking chamber. said cham` ber having an entrance opening `with a cooperating baffle Wall Within the chamber for protecting the carriers therein from the heat of the radiating surfaces until the carrier has reached the highly heated part of the oven. thereby to cause a sudden exposure of the carrier and its contents to the full heat of the oven,

l0. A continuous baking oven having a baking chamber, means for heating the same, an endless traveling conveyor with carrying devices for the materials to be baked, upright entrance and exit passages for said conveyor opening to the exterior near the bot tom and at the saine side of the baking chamber, said carrying devices tending to close said passa against the enit of hot air or the entrance of cold air.

il. A. continuous baking oven comprising in combination, a baking chamber. an cndless conveyor for the materials to be baked, means for guiding the conveyor, `through said oven in a circuitouspath, a combustion chamber having refractory Walls beneath the baking chamber, a heating chamber between the combustion chamber and the baking chamber, and metallic radiating surfaces having an agg egate area greater than the area of the space occupied by the baking chamber and including a metallic bottom Wall for the baking chamber exposed to the heat of said heating chamber.

l2. A continuous baking oven having a baking chamber, a traveling conveyor, a combustion chamber beneath the oven provided With arched refractory Walls, a ra-` dieting floor surface for the baking chamber, and lateral exit ports for said combustion chamber intermediate its ends presenting a greater' cross-sectional area at the side of the arch for the discharge of the gases than at the top thereof.

13. A continuous baking oven'comprising in combination a baking chamber, means for heating the same, a flexible traveling conveyor having a series of carriers pivotally suspended thereon, trays on said carriers, a series of pans on each tray, and devices to automatically discharge the baked materials comprising a movable device in each pan to dislodge the baked materials in the pan, means to actuate the same, and means acting cooperatively to tilt the pan with relation to the conveyor.

la. A continuous baking oven comprising in combination a baking chamber, means for heating the same, a flexible traveling conveyor having a series of carriers pivotally suspended thereon and normally held by gravity in all positions of the conveyor, each on its pivotal support in depending relation to said conveyor, means automatically to tilt the carrier out of its gravity suspended position, and a movable dislodging device coordinately actuated to dislodge the baked material from its carrier.

l5. ik continnolils baking oven comprising in (,foinbination a baking chamber, a t raveling conveyor for the materials to be baked, means to guide said carrier through said chamber in a succession of up and down paths providing a plurality of reverse turns with spaces between resulting counterpaths of the conveyor, alternate spaces being unobstructed at the bottom, and a plurality of upright flue chambers extending into the baking chamber in said alternate unobstructed spaces and provided with raiiliating surfaces adapted to be heated by the ascending products of combustion.

16. A, continuous baking oven comprising in combination a baking chamber, a traveh ing conveyor for the mat 'Lials to be balv d, means to guide said carrier through aidl chamber in a succession of up and down paths providing a plurality of reverse turns with spaces between resulting counteriL/iaths of the conveyor, alternate spaces being unobstructed at the bottom, a radiating bottom Wall for said baking chamber, and a plurality of upright flue chambers extending from the bottom Wall into the baking chainber in said alternate unol'istructcd spares and provided with radiating ed to be heated by the ascent( of combustion.

17. ,fr continuous ba ing oven comprising' in combination a baking chamber, a traveling conveyo for the materials to be baked. means to guide said carrier through said chamber in a succession of up and down paths providing a ihnality of reverse 'turns with spaces between resulting coun'terpat1 ilS of the conveyor, alternate spaces being unobstructed at the bottom, a radiating bot` tom Wall for said baking chamber vith a heating space below the same, a plurality of uprug it 'fine chambers extending into the baking chamber' in said alternate unobstructed spaces and provided with radiating surfaces adapted to be heatel by the products of combustion ascending from said heating space, and a separate heat dist=.i but ing` chamber provided with refractory Walls beneath said heating space.

18. A continuous baking oven comprising a baking chamber, a combustion chamber, a traveling conveyor having an elongated path presenting substantially parallel portions within the baking chan'iber, heating devices comprising substantially parallel radiating plates extending transversely the baking chamber and between parallel portions of said conveyors path.I said plates forming between them a flue chamber through Which the products of combustion are adapted to pass` and within said Chamber to distribute the products ot combustion over the surfaces of said plates.

19. A continuous baking oven comprising in combination, a baking chamber, an i less traveling conveyor Awith carrying devices for the materials to be baked, inea ns to guide said conveyor in said chamber through a circuitous path providing alternatelj; up and down paths, a heating chamber beneath said baking chamber and separated therefrom by a n'ietallic heat radiat nf'all, and one or more tlue cliambcrs heat radiating walls extending upward from said heating chamber between successive up and down paths of the conveyor.

20. A continuous baking oven having s. baking cl'iamber, a radiating bottom wall 'for said chamber, an endlessv caimveyor having carriers with .meins to guide the saine into and out of the baking cli t the same end and near the bottoni tl is, .sa id cha-nn ber having provision to oppose the escape of heat radiated. from said tioor and the entrance of cold air with the crit and entrance of the carriers.

2l. A continuous baking oven having a substantially enclosed baking ch amber, heating means, an endless conve yor with carriers and devices to guide the same into and out of the chamber, said guiding devices providing for the entrance and exit of said carriers be yond the peripheral limits of the baking chamber in horizontal paths near the bottoni and at the same end of the cliamber but hat ing their Succeeding and preceding movements respectively in substantially vertical paths.

22. A. baking oven having a baking cha1nber, a traveling conveyor, extended radiating surfaces in the baking chamber for the indirect heating thereof and including an underlying radiating floor, distributed fine exits to Withdraw the heated gases from said tloor and assist in the diffusion thereof over the floor, said flue exits also presenting radiating surfaces exposed to the baking chamber, and a combustion chamber havingl refractory Walls beneath the Hoor and provided with means to distribute the gases to the fioor through multiple paths to diffuse the same over the floor.

Si baking oven having a baking chamber, a traveling conveyor, radiating surfaces exposed to the interior of said chamber for the indirect heating thereof comprising extended radiating Walls underlying said conveyor, a heat distributing chamber having refractory Walls underlying the baking chamber, and means for distributing the heated gases from the chamber to the underlying radiating Walls to cause the diffusion of the heated gases over the same.

24e. A baking oven having a baking chamber, a traveling conveyor, radiating),- surfaces exposed to the interior of said chamber for the indirect heating thereof and comprising a radiating floor Wall, a heating space beneath the floor Wall, and a heat distributing chamber having means for distributing the heated gases from the chamber to the heating space to cause a diffusion of the heated gases over the floor Wall.

25. In a continuous baking oven, the combination with a baking chamber' of a conveyor for the materials to be baked, means for guiding the same through the chamber in an elongated path exposing to the heat of the chamber a length of conveyor relatively great as compared with the length of the chamber, a radiating floor underlying the conveyor and so related to the capacityv of the conveyor as to provide heat proportioned to the materials conveyed through the chamber, a chamber having refractory Walls beneath the fioor and separated therefrom by a heating space, means for diffusing and distributing the products of combustion to the heating space and the floor, and means at the margin of the floor for carrying oli' the products of combustion. v

26. A baking oven having in combination a baking chamber, an endless traveling conveyor for the materials to be baked, means for guiding the same through the chamber in an elongated path exposing to the heat of the chamber a length of conveyor relatively great as compared with the length of the chamber, a combustion chamber provide ed with refractory Walls, a flue chamber having radiating Walls underlying` the conveyor and exposed to the baking chamber and communicating With the combustion chamber by means Which `provide for dii'- usion of the gases over the radiating Walls, said Walls being so related to the capacity of the conveyor as to provide heat proper'- tioned to the materials conveyed through the chamber, and a` plurality of exit iiue chambers having radiating Walls exposed to the baking chamber and providing for further' dii'l'usion of the heated gases over the underlying radiating Walls.

27. A baking oven having a baking chamber, a traveling conveyor, means for guiding the same through the chamber in an elongated path exposing' to the heat of the chamber a length of conveyor relatively great as comparedvvith the length. of the chamber, a heat distributing chamber through which the products of combustion pass, radiating surfaces underlying the conveyor for indirectly heating the baking chamber, said surfaces being so related to the capacity of the conveyor as to provide heat proportioned to the materials conveyed through the chamber, and exits distributed lengthwise the distributing chamber to distribute the high temperature products of combustion to the radiating surfaces at different points thereon.

28. A continuous baking oven having in combination a baking chamber, an endless conveyor for the materials to be baked, means for guiding the conveyor through the chamber in an elongated path exposing to the heat of the chamber a length of conveyor relatively great as compared with the length of the chamber, a combustion chamber having refractory Walls beneath the baking chamber, radiating surfaces for the baking chamber having an aggregate area greater than the area of the space occupied by the baking' chamber and comprising radiating Walls underlying the conveyor, said surfaces being so related to the capacity of the conveyor as to provide heat proportioned to the materials conveyed through the chamber, and means to distribute the heated gases from the combustion chamber to the underlying radiating Walls through multiple paths to diiiuse the gases over the same.

29. A continuous baking oven having in combination a baking chamber, a traveling conveyor, means for guiding the same" through the chamber in an elongated path exposing to the heat of the chamber a length of conveyor relatively great as compared with the length of the chamber', an underlying ilue chamber With radiating Walls so related to the capacity ot' the conveyor as to provide heat proportioned to the materials conveyed through the chamber, said chamber also having a plurality of flue exits to provide divided paths and diffusion of the gases over the radiating Walls, and a separate heat distributing chamber With means to distribute the gases to the line chamber through multiple paths to further diEuse the same over said underlying radiating Walls.

30. A continuous baking oven comprising in combination a baking chamber, the conveyor 23 With trays 27, means for guiding the same through the chamber in an elongated path exposing to the heat of the chamber a length of conveyor relatively great as compared with the length of the chamber. the rar'liating surfaces comprising the floor 2l, said surfaces being so related to the capacity of the conveyor as to provide heat proportioned to the materials conveyed through the chamber, the underlying heating chamber 45, the combustion chamber 85 With its Walls 37, the distributing openings 7l, and the burner 39.

ln testimony whereof, lf have signed my name to this specification.

ARTHUR H. BALLARD.

Certificate et' Correction.

lt is hereby certified that in Letters Patent No. 1,434,035, granted October 3l, 1922, upon the application of Arthur H. Ballard, of Boston, Massachusetts, for an improvement in Apparatus for Baking, an error appears in the printed specilication requiring correction as follows: Page 6, lines 129 and 130, and page 7, line l, claim 6, strike out the Words separate from but communicating With the combustion chamber, and insert the saine to ii'ollou7 the Word chamber in line 3, page 7, same claim; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oilce.

Signed and sealed this 28th day of November, A. D., 1922.

[SEAL] Kant rENNiNG,

Acting omm'issoar of Patents. 

